package model;

//用于博客表的基本操作

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class BlogDao {
    //1.往博客表里插入一个博客
    public void insert(Blog blog){
        //JDBC代码
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            //1.和数据库建立连接
            connection = DBUtil.getConnection();
            //2.构造sql语句
            String sql = "insert into blog values (null, ?, ?, ?,now())";
            statement = connection.prepareStatement(sql);

            statement.setString(1, blog.getTitle());
            statement.setString(2, blog.getContent());
            statement.setInt(3, blog.getUserId());
            //3.执行sql
            statement.executeUpdate();


        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            //4.关闭连接，释放资源
            DBUtil.close(connection,statement,null);

        }



    }

    //2.能够获取到博客表的所有博客信息（用于在博客列表页中显示）
    public List<Blog> selectAll(){
        List<Blog>  blogs = new ArrayList<>();
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "select * from blog order by postTime desc";
            statement = connection.prepareStatement(sql);
            resultSet = statement.executeQuery();
            while (resultSet.next()){
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                //这里需要针对内容进行阶段，如果太长去掉后边的内推
                String content = resultSet.getString("content");
                if (content.length() > 50){
                    content = content.substring(0,50) + "...";
                }
                blog.setContent(content);
                blog.setUserId(resultSet.getShort("userId"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));

                blogs.add(blog);
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }


        return blogs;
    }

    //3.能够根据博客id获取到指定博客内容
    public Blog selectOne(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;


        try {
            connection=DBUtil.getConnection();
            String sql = "select * from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId); //把第一个问号设置为blogId

           resultSet = statement.executeQuery();
            //此处使用主键来作为查询条件，查询结果要么是1要么是0
           if(resultSet.next()){
               Blog blog = new Blog();
               blog.setBlogId(resultSet.getInt("blogId"));
               blog.setTitle(resultSet.getString("title"));
               blog.setContent(resultSet.getString("content"));
               blog.setUserId(resultSet.getShort("userId"));
               blog.setPostTime(resultSet.getTimestamp("postTime"));
               return blog;
           }


        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }


        return null;
    }

    //4.根据博客id从博客表中删除博客
    public void delete(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            connection = DBUtil.getConnection();
            String sql = "delete from blog where blogId = ?";
            statement = connection.prepareStatement(sql);

            statement.setInt(1,blogId);
            statement.executeUpdate();


        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,null);
        }



    }


    //增删查，没有改

}
